The mortality modeling and forecasting is of fundamental importance in many areas, such as funding of public and private pensions, life insurance, the care of the elderly or the provision of health services. The book is an attempt to approach this subject from a new theoretical point of view, using theory of stochastic differential equations, theory of fuzzy numbers and complex numbers. These notes are addressed to tertiary students, doctoral students and specialists in the fields of demography, life insurance, statistics and economics.